Loblolly pine (Pinus taeda L.) seedlings were grown in competition with native weeds using soil and seed bank collected from recently chopped and burned areas near Appomattox, Virginia. One-year-old seedlings were planted and weeds allowed to germinate from the native seed bank while being exposed to CO(2) (ambient and elevated - approximately 700 ppm) and water (water stressed and well watered...

Weeds are a major constraint to the success of dry-seeded rice (DSR). The main means of managing these in a DSR system is through chemical weed control using herbicides. However, the use of herbicides alone may not be sustainable in the long term. Approaches that aim for high crop competitiveness therefore need to be exploited. One such approach is the use of high rice seeding rates. Experiment...

a field experiment was conducted to study the spatial relationships between weed seed bank and population and their distribution models in sugar beet crop (beta vulgaris) in 2009 at motahari  agricultural research station of karaj. sampling from seed bank before sugar beet drilling and weed population in three stages during the growing season were done using square (50*50 cm) and rectangle (25*...

Environ. Enlomol. 12: 2%-298 (1983) ABSTRACT Sweep-nel sampling and pilfalllrapping were used 10 survey insects in weedy and weedfree soybean habitals. Weedy soybean habitats consisted of (I) grassy soybeans; (2) soybeans with broadleaf weeds; and (3) soybeans with broadleaf weeds and grasses. Insect species diversity was greater in weedy soybean habitats than in weed-free soybeans. Greatest di...

Agriculture is the process of managing plant communities to obtain useful materials from the small set of species we call crops. Weeds comprise the “other” set of plant species found in agroecosystems. Although they are not intentionally sown, weed species are well adapted to environments dominated by humans and have been associated with crop production since the origins of agriculture (Harlan,...

the effect of nitrogen (n) levels on n uptake by high weed densities at early growth stages of corn (zea mays l., cv. double cross 370) was investigated for two years (2008-2009) at the agricultural research station of shiraz university. the experiment was arranged in a split-plot arrangement in the randomized complete blocks design with three replications. two levels of weed control (weedy and...

BACKGROUND The efficacy of pre-emergence herbicides within fields is spatially variable as a consequence of soil heterogeneity. We quantified the effect of soil organic matter on the efficacy of two pre-emergence herbicides, flufenacet and pendimethalin, against Alopecurus myosuroides and investigated the implications of variation in organic matter for weed management using a crop-weed competit...